OBJECTIVE： To optimize the formulation of Dimemorfan phosphate tablets. METHODS： Using 60 min dissolution rate of dimemorfan phosphate as index， L9（34） orthogonal test was used to optimize the amount of starch， microcrystalline cellulose， croscarmellose sodium and concentration of HPMC E5 solution. The friability， hardness， 60 min dissolution rate and main component were detected. The similarity of dissolution curves of Dimemorfan phosphate tablets was compared with that of imported tablets in 0.1 mol/L hydrochloric acid， pH 6.8 phosphate buffer， water and pH 4.0 acetate buffer. RESULTS： The optimized formulation of Dimemorfan phosphate tablet （1 000 tablets） was composed of dimemorfan phosphate 10 g， starch 60 g， microcrystalline cellulose 40 g， 10％ HPMC E5 solution and croscarmellose sodium 25 g. The friability， hardness， 60 min dissolution rate and main component of 3 batches of Dimemorfan phosphate tablets prepared by optimized prescription were 0.42％-0.58％， 9.8-10.5 kg， 94.89％-96.21％ and 99.21％-99.52％， respectively.  In 4 dissolution mediums， similar factors f2 of dissolution curves between prepared tablets and imported tablets were above 50. CONCLUSIONS： Dimemorfan phosphate tablets were prepared successfully. The optimized formulation is rational. The dissolution behavior of prepared tablets is similar to that of imported tablets in vitro.